Early admission is better–the time to admission (TTA) is associated with one-year mortality in hip fracture

Abstract

Objective: This study evaluated the probable association between time to admission (TTA) and one-year mortality in geriatric hip fractures. Methods: Older adult patients with hip fractures were screened between January 2015 and September 2019. The demographic and clinical characteristics of the patients were collected at the largest trauma center in northwest China. TTA can be obtained from the medical record system and converted into a categorical variable. Multivariate binary logistic regression and generalized additive model were used to identify the linear and nonlinear association between TTA and one-year mortality. Analyses were performed using EmpowerStats and the R software. Results: Two thousand three hundred and sixty-one patients who met the criteria were finally included. There were 1618 (68.53%) female and 743 (31.47%) male patients. All patients were divided into three groups according to their TTA. The proportions of patients with low (<=6 h), middle (>6, <=24 h), and high (>24 h) waiting times were 995, 654, and 712, respectively, and the corresponding one-year mortality rates were 62 (6.23%), 72 (11.01%), and 82 (11.52%). We found a curve relationship between TTA and one-year mortality by two-piecewise linear regression, and 9 hours was an inflection point. When TTA was less than 9 hours, the one-year mortality of patients increased by 9% for every 1-hour increase in TTA (OR=1.09, 95%CI: 1.03-1.16; P<0.01). When TTA was greater than 9 hours, the mortality of patients no longer increased with the rise of TTA (OR=1.00, 95%CI:1.00-1.00; P=0.26). Conclusion: TTA is a probable predictor of one-year mortality. We found that 9 hours is an inflection point. If TTA is less than 9 hours, the mortality rate of patients will be lower. If it takes more than 9 hours, the mortality will be higher. Therefore, the elderly who are found to have possible hip fractures should be admitted to the hospital as soon as possible.